modTime  time.Time
		days     ExpirationDays
		expected time.Time
	}{
		{
			time.Date(2020, time.March, 15, 10, 10, 10, 0, time.UTC),
			4,
			time.Date(2020, time.March, 20, 0, 0, 0, 0, time.UTC),
		},
		{
			time.Date(2020, time.March, 15, 0, 0, 0, 0, time.UTC),
			1,
			time.Date(2020, time.March, 17, 0, 0, 0, 0, time.UTC),
		},
	}

	for i, tc := range testCases {